Lecture 16- Forearm and Hand 2

Question 1

Label this

Answer 1

1. Flexor carpi radialis
2. Flexor pollicis longus
3. Compartment which contains both tendons of flexor digitorum superficialis, and flexor digitorum profundas

Question 2

What is the name of the fibrous band at the bottom, and what is the yellow thing in the middle that runs beneath the band

Answer 2

Bottom band is the flexor retinaculum, and the yellow structure is the median nerve

Question 3

For clinical purposes, what are we calling the same as the flexor retinaculum even though its not?

Answer 3

Transverse carpal ligament

Question 4

What are the attachments for the flexor retinaculum?

Answer 4

• Tubercle of scaphoid
• Tubercle of trapezium
• Pisiform bone
• Hook of hamate

Question 5

What are the contents of the carpal tunnel?

Answer 5

Long flexor tendons of digits, and the median nerve

Question 6

What is the common origin for the extensor muscles of the forearm?

Answer 6

Commin origin is around the lateral epicondyle, and also the posterior surface of ulna and interosseous membrane

Question 7

What is the extensor of the thumb?

Answer 7

Extensor pollicis longus (forms posterior side of snuff box also)

Question 8

What extends the index finger, and what extends the 5th finger

Answer 8

Index finger = Extensor indicis, 5th finger = Extensor digiti minimi

Question 9

Where is the common origin for the flexor muscles of the forearm?

Answer 9

Medial epicondyle

Question 10

Describe the structure of extensor digitorum

Answer 10

It’s muscle belly is in the forearm, and distally it has four tendons which each act as a main extensor for each finger

Question 11

What tendons are found in the first extensor compartment?

Answer 11

Tendon of abductor pollicis longus and extensor pollicis brevis

Question 12

Which tendons lie in the second extensor compartment?

Answer 12

Extensor carpi radialis longus, and extensor carpi radialis brevis

Question 13

Which tendon is found in the 3rd compartment on the extensor side of the wrist?

Answer 13

Tendon of extensor pollicis longus

Question 14

Which muscle do the set of 4 tendons in the 4th extensor compartment belong to? And there is one more tendon, what does this belong to?

Answer 14

Extensor digitorum, and in the 4th compartment there is also the extensor indicis

Question 15

Which tendon lies in the 5th extensor compartment?

Answer 15

Extensor digiti minimi

Question 16

Which tendon lies in the 6th extensor compartment

Answer 16

Tendon of extensor carpi ulnaris

Question 17

What three muscles are in the Thenar eminence?

Answer 17

• Flexor pollicis brevis
• Abductor pollicis brevis
• Opponens pollicis

Question 18

Which muscles belong in the hypothenar eminence?

Answer 18

• Flexor digiti minimi
• Abductor digiti minimi
• Opponens digiti minimi

Question 19

Which muscle is this?

Answer 19

Adductor pollicis

Question 20

Excluding the muscles of the thenar and hypothenar eminence, what other intrinsic muscles are there in the hand?

Answer 20

• Adductor pollicis
• Lumbricals and interossei

Question 21

What is the proximal and distal attachment for the lumbricals?

Answer 21

The lumbricals proximally attach to the tendons of flexor digitorum profundus, and their tendinous slips pass dorsally to attach to the extensor expansion

Question 22

What is the proximal and distal attachment of the interossei muscle?

Answer 22

The interossei muscle attaches proximally to the metacarpal bones, and distally attaches to the extensor expansion

Question 23

What movement does the palmar interossei perform, and what movement does the dorsal interossei perform?

Answer 23

• Palmar interossei = adducts fingers (PAD)
• Dorsal interossei = abducts fingers (DAB)

PALMAR INTEROSSEI ARE DEEP TO LUMBRICALS

Question 24

What are the 5 superficial muscles on the flexor aspect of the forearm?

Answer 24

• Pronator teres
• Flexor carpi radialis
• Palmaris longus
• Flexor digitorum superficialis
  
  • Flexor carpi ulnaris

Question 25

What are the 3 deep muscles on the flexor aspect of the forearm?

Answer 25

• Flexor pollicis longus
• Flexor digitorum profundas
  
  • Pronator quadratus
    *

Question 26

Why is compartment syndrome very bad, not healthy, u die

Answer 26

Compartment syndrome is caused by tissue damage, and this leads to the compartment(s) getting swollen causing the nerves and muscles to become compressed. This can cause them to become necrotic, and eventually dying.

Question 27

What is the key supinator of the eblow when it is at 90 degrees?

Answer 27

Biceps brachii

Question 28

Describe how force is transmitted in the upper limb

Answer 28

Most of the force is recieved by the second and third metacarpals, and this force is then transmitted via the trapezoid and capitiate, then the scaphoid and lunate, and then the radius, and then the ulna via the interosseus membrane, and then the humerus via the humeroulnar joint

Force transmitted to other metacarpals is transmitted to this central anchoring line due to the orientation of the ligaments connecting the bases of metacarpals and carpal bones